No, you’re not imagining it. I am friendlier and more influential now.

I owe it all to Dale Carnegie, the failed actor from Missouri who discovered he had a knack for jazzing up people’s confidence. His foundational work, “How to Win Friends & Influence People,” blasted off in 1936, but for anyone who wants a pill-sized dose of encouragement, a “mini abridged edition” is being released this week to celebrate the book’s 80th year.

Dale Carnegie reads from “How to Win Friends & Influence People” at the national convention of the Dale Carnegie Institute of Effective Speaking and Human Relations, in Chicago in 1955. (AP)

You could call “How to Win Friends & Influence People” the grandfather of America’s self-help movement, except this grandfather is running circles around the rest of the industry, selling 300,000 copies last year. That was all news to me. Until recently, I had assumed Carnegie’s book was just another fragile antique from the 1930s, like the electric tube radio. But, no, it turns out that his corrective advice to wallflowers and jackasses is considerably more durable.

My younger daughter, a dancer living in New York, was amused the first time she saw her boyfriend reading “How to Win Friends & Influence People.” But it didn’t help. Her next boyfriend was nothing like the first one, except that he, too, was reading “How to Win Friends & Influence People.” By the time she noticed a third boyfriend reading “How to Win Friends & Influence People,” she began to think that maybe it was time to get out of New York.

Her plight inspired me to take a deep dive into Carnegie’s pool of wisdom to taste his elixir for myself.

(Simon & Schuster)

Clearly, much of the man’s persistence stems from the ability of his heirs and disciples to keep repackaging his common-sense advice. Nowadays, the decision to study Dale Carnegie begins with deciding which reincarnation of Dale Carnegie to study. The original book, based on his 14-week public-speaking course, went through dozens of printings. His late wife, Dorothy, described her husband as “a tireless reviser,” a habit that continued even after his death in 1955. The book was substantially updated in 1981, omitting a chapter on “Making Your Home Life Happier” that advised the husband to give his wife “money to spend entirely as she chooses,” while warning the wife to “give your husband complete freedom in his business affairs,” advice that would have ruined essentially every episode of “I Love Lucy.”

His only child, Donna, published a companion edition in 2005 called “How to Win Friends & Influence People for Teen Girls” — an intimation of such loneliness that it kind of breaks your heart. That tightly targeted title is emblazoned on the pink cover in purple glitter, which cost me a few odd stares on the subway, but that’s no matter because now I know How To Use Negative Energy As Rocket Fuel.

(Simon & Schuster)

Most recently, in 2011, Dale Carnegie & Associates published “How to Win Friends & Influence People in the Digital Age,” an acknowledgment that Facebook has changed what it means to get people to “like” you. But the book begins with a sentence unlikely to win friends or influence people in any age: “Ask both Adolf Hitler and Martin Luther King Jr. for a basic definition of influence and you might get similar answers.”

You might, but for all his Associates’ efforts to keep him hip — including, of course, an app — Carnegie’s own voice remains the most potent. The son of a farmer, Carnegie wrote in a direct, homespun style that’s 100 percent wit-free. “How I wish a book such as this had been placed in my hands twenty years ago!” he exclaims in the introduction. What follows is a breathlessly earnest sermon on the effectiveness of smiling, giving praise, avoiding criticism and remembering people’s names.

Carnegie nods to Ben Franklin’s life advice in “The Autobiography,” but he remains immaculately untouched by the Founding Father’s irony. Each short, wildly optimistic chapter — e.g. “Do This and You’ll Be Welcome Anywhere” — is bolstered by testimonials that range from, say, Napoleon, an emperor in France, to C.M. Knaphle Jr., a salesman in Philadelphia. Again and again, we’re shown how expressing interest in other people and appealing to their vanity has — “presto!” — reshaped nations, harmonized factories and increased sales.

“Be a good listener.”

“Show respect for the other person’s opinions.”

“If you are wrong, admit it.”

“Be sympathetic with the other person’s ideas and desires.”

Such basic advice, presented with such confidential enthusiasm, inspires two questions: First, are there really people who don’t know this? And second, are there really people who don’t know this who could learn it by reading a book?

Carnegie, at least, was optimistic that such pliant but uninformed souls would always exist, and who can argue with tens of millions of copies and still going strong? The result of studying “erudite tomes,” “hundreds of magazine articles” and “countless biographies,” the admonitions he sets down here are “principles” — not “mere theory” — that “work like magic.” Toward the end, he advises “leaving a friendly trail of little sparks of gratitude” and then observing “the sheer witchery of praise.”

That emphasis on the miraculous quality of his extraordinarily ordinary advice may be his most profound and lasting influence on the self-help industry. Just a few months after “How to Win Friends” appeared, Napoleon Hill published “Think and Grow Rich,” which works if, like Hill, you think of a book that grows to 100 million copies. Then in 1952 came “The Power of Positive Thinking,” by Donald Trump’s onetime pastor, Norman Vincent Peale, and the floodgates positively opened. Now, every self-help book sports the magical transformation that Carnegie promised, from Elizabeth Gilbert’s “Big Magic” to Marie Kondo’s “The Life-Changing Magic of Tidying Up” — enough to solve all the problems of your love life and your sock drawer. Indeed, one would assume from the books on sale that the only thing keeping us from enjoying a “4-Hour Workweek” or speaking “The Five Languages of Love” or scaling “The Six Pillars of Self-Esteem” or practicing “The 7 Habits of Highly Effective People” was our stubborn unwillingness to avail ourselves of “The Secret.”

(Simon & Schuster)

Mocking these peddlers of personal growth is easy, but that’s no way “To Make People Like You Instantly” (Chapter 6). Besides, there’s something fascinating about the unresolved tension in Carnegie’s book, a contradiction that runs straight through American culture. Almost every chapter emphasizes that people are driven by vanity and self-interest, flaws that Carnegie’s savvy students can use to their own advantage. Yet his system is predicated on the assumption that people are basically good and can be inspired by genuine kindness to behave better.

Yes, genuine kindness. His title may cast a cynical shadow over the whole enterprise, but Carnegie insists on sincerity. “No! No! No!” he cries early on. “I am not suggesting flattery.” He requires that his students “give honest and sincere appreciation.” The key to success is understanding others’ points of view and finding solutions that accommodate their needs. Donning the mantle of a secular messiah, he proclaims, “I am talking about a new way of life.”

Is some modern-day Eddie Haskell reading this updated paperback today and extracting only Carnegie’s verbal tricks for ingratiating himself and manipulating others? Of course. But as church attendance continues to sink in America, maybe the ethical counsel found in “How to Win Friends” can take up some of the slack. God knows people are thirsty for basic enlightenment, and it can’t all come from hot yoga. A few years ago, a commencement speech by George Saunders went viral with its simple plea for kindness. In an age so poisoned by incivility, especially in a capital tyrannized by an egomaniac obsessed with denigrating all opponents, it’s not such a bad thing to review — or learn — the basic principles of humane behavior.